thomson



(No Model) 2 Sheets-Sheet 1. E. THOMSON.

AIR BLAST ATTACHMENT FOR GOMMUTATORS OF DYNAMO ELEGTRIG MACHINES.

No. 273,406. atented Mar.6,1883.

Fig.1.

ATT EST INVENTDRI (No Model) 2 Sheets-Sheet 2.

E. THOMSON.

AIR BLAST ATTACHMENT FOR COMMUTATCRS 0F DYNAMO ELECTRIC MACHINES.

No, 273,406. Patented Mar.6,1883.

ATTES-T: INVENTUH: WEAR i M,

UNITED STATES PATENT ()FFICE.

ELIHU THOMSON, OF NEW BRITAIN, CONNECTICUT, ASSlGNOR "0 THE AMERICAN ELECTRIC COMPANY, OF SAME PLACE.

AIR-BLAST ATTACHMENT FOR COMMUTATORS OF DYNAlVlO-ELECTRIC MACHlNES.

SPECIFICATION forming part of Letters Patent No. 273,408, dated March 6, 1888.

(No model.)

To all whom it may concern:

Be it known that I, ELIHU- THOMSON, a citizen of the United States, and a resident of New Britain, in the county of Hartford and State of Connecticut, have invented certain new and usefullmprovements in Air-BlastAttachments for Oommutators of Dynamo Electric Machines, of which the following is a specification.

My invention is designed to furnish a simple and effective means of carrying out the invention patented to me by Letters Patent of the United States No. 265,936, dated October 10, 1882. In that patent I have set forth how a blast of air or of any insulating liquid or fluid may be used to maintain theinsulation of two plates or surfaces having a difference of potential or polarity, and I have described in particular the method of preventing flashing between the segments of a commutator by means of a blast of air applied to the spaces between the commutator plates or segments immediately after the commutator-brush passes from one segment to another.

My present invention is an improvement upon the devices described in my prior patent, and provides a means that is practically a part of the machine, and is little liable to get out of order.

My invention consists in mounting the device for generating the air-blast directly upon the armature-shaft or attaching it directly to the same, said devices being connected to suitable air-ducts or blast directors or jets, whereby the blast is directed upon the commutator at the points where the slots pass the brushes.

My invention consists, further, in the combination, with suitable air ducts or jets arranged to direct a blast of air upon the commutator, of rotary air-blast apparatus mounted on the armature-shaft.

My invention consists, further, in the combination of rotating vanes or wings and a casing within which said vanes or wings move, the casin g or the wings, as is found desirable, being connected to the armature-shaft, so as to revolve therewith while the other parts are stationary, and suitable air ducts and jets connected with the casing and suitably applied to the commutator.

My invention consists, further, in the combination, with the armature-shaft, of one or more valves, wings, or vanes mounted on the armature-shaft and arranged to slide freely in aradial direction, and a stationary casing of suitable form, in contact with the interior surfaces of which the vanes or wings are held by contrifu gal action.

My invention further consists in the combi nation, with the airjets or pipes directed upon the commutator, of a joint of insulating material connecting them with theair-supply pipes or ducts.

My invention consists, also, of certain combinations and details of construction, that will be first fully described, and then pointed out in the claims.

In the accompanying drawings, Figure 1 is a top view of the air-blast attachment and the commutator to which it is applied, the commutator being a three-segment commutator, such as is described in prior patents granted to me, and constructed and mounted in the manner described in another of my applications. Fig. 2 is an end view of the commutator and the air-blast attachments. Fig. 3 is a longitudinal section on the line of the armatureshaft. Fig. 4 is a transverse section through the rotary air-blast apparatus on the line ()"O of Fig. 1.

Upon the shat'tX of the machine, Fig. 1, I place the commutator K, as-usual, and attach thereto the armature terminals t in any wellknown way. The commutator K is preferably one in which the segments are mounted in free air upon a light frame-work, and consists essentially, as described by me in one of my applications, of two disks or plates, 3 3, secured to the armature-shaft, and connected by a series of rods or bars, at 4: 4, to which the segments are suitably secured, and through which connection is made between the armature terminals tit and the commutator-segments. lhe shaft X bears the revolving portion of the blast mechanism. B is the stationary box or casing inclosing the revolving portions of the same, which box B is supported in any suitable manner from any portion of the machine. From the box B jets J are led and directed upon the commutator, so that the erases air will pass into the slots between the segtimed or simultaneous with the passage of the ments just as said slots pass from beneath the 'commutator-brushes. There are of course two such jets in ordinary cases, placed diametrically opposite. The jets are connected with the air ducts or pipes leading from the airblast generator by interposed couplings or sleeves S, of rubber or other suitable insulat ing material, to prevent leakage of current, and possible shocks in touching simultaneously thejets and commutator-brushes. Thejets are made, if preferred, adjustable in position across the face of the commutator, and are set in place by a clam p-screw, V, which bears against a pipe, J, sliding in a duct in the case B, as shown. To facilitate the adjustment of the jets J upon the commutator circumferentially, theboxB is also made adjustable around the shaft by screws or bolts 0, which pass through or into elongated slots in the support 1, and since the box B carries the jets J by clamping said box B to its support in any position, a permanent setting of the jets may be secured. Fig. 2 shows the same parts viewed from end of the shaft, where also the jets J J are seen to be directed toward the tips of the comrnutatoubrushes E F, respectively.

The construction and method of mounting the air-blast-generating devices or blower are more fully shown in section, Figs. 3 and 4:.-

Upon the shaft X is carried, but not rigidly, a slotted barrel or cylinder, D, the hub of which has a key-way, a, in which a short lug or spline, b, on the shatt engages. The opening in D is slightly larger than the shaft, thus allowing play of the latter endwise and of D sidewise without cramping. In the case of a three-segment commutator three slots are cut radially in the disk or barrel D, and in these slots are three movable wings. valves, or pistons, preferably of hard rubber, \V W \V, Fig. 4. During rotation these wings are held outward from the axis by centrifugal force. The shape of the wings and disk D is such as to secure a moderate titof parts with the outer case, except where the configuration is different. The metal case B is formed interiorly, as in Fig. at, of elliptical or oval outline, where two jets only are used with two commutatorbrushes, but may be readily modified to suit the case of four or more jets. The direction of revolution is as shown by arrows. Air-inlets I I, covered with one or more wire-gauze diaphragnis to intercept dust, are provided, as shown. The outlets are of course connected with thejet-pipes J J.

In Fig. 3 the arrangement of jets and conduits thereto is exhibited. \Vhen the shaft X is revolved rapidly, rotary movement is imparted to the disk D and. wings W V W, Fig. 4, and the latter, beingcarried outward into the crescent-shaped spaces, act as pistons to propel puffs of air from the inlets I l to the jetpipes J J. There are three pufifs from each jet in one revolution, and the position of the lugb on the shaft is made such thatthepnti's are slots of the commutator past brushes E I as aforesaid. The preferred support of the outer casing or box, B, is from a plate, P P, upon the bearing A of the machine, said plate having slots curved circumferentially for the set ting of the box B in proper position, as before described, and having also recesses in its face forming the communication between the airspace in which the wings or valves move and the openings in which the pipes J J are set, as shown in section in Fig. 3.

By the construction as above described jets or puffs of air are obtained simultaneous with the passage of the com m ntator-slots from beneath the tips of the commutator-brushes, and at the same time the wear of the moving parts is reduced to almost nothing. Very little lubrication of the blast mechanism suffices. In fact, I find that snfiicientoil will ordinarily work its way form the hearing A to -l;eep the parts in good order. No restriction is put upon the rotation or end play of the shaft X when such play exists. The disk D is free to accommodate itself so as to move truly with the box B. I find advantage in the use of hardrubber wings \V W W on account of immunity from wear, lightness, ease of construction, and comparative freedom from expansion, should the parts become heated from the box A. My invention suffices to obtain a forcible blast, if need be,and is run with entire safety at high speeds.

I do not limit myself to placing the revolving parts of the air-blast devices directly upon the armature-shaft, although such arrange ment is preferable. An air-blast device constructed and connected to the air-jets in the manner described would still be of value if not directly connected to or revolved from the armature-shaft.

What I claim as my invention is" l. The combination, with the commutator, of air-jets or directors applied thereto, as and for the purpose described, and air-blast devices mounted on the armature-shaft and connected with saidjets.

2. The combination, with suitable air ducts orjets arranged to direct a blast of air upon the commutator, 0t rotary air-blast apparatus mounted on the shaft carrying said commutator.

3. The combination, with air-jets directed upon the commutator for a dynamo-electric machine, of abox or casing and wings or vanes fitted therein, said box or said wings being stationary, as maybe desired, while the movable portion is mounted on the armature-shaft, and air ducts or conduits connecting the casing with the air-jets.

4. Thecombination, with the armature-shaft, of one or more vanes or wings mounted in any suitable manner so as to be capable of radial motion, a casing within which said wings revolve, and with whose interior surface they are held in engagement by centrifugal action,

and air-jets directed upon the commutator and connected with said casing.

5. The combination,with the air-jets directed upon the commutator, of air-blast apparatus giving impulses or puffs simultaneously with the passage of the commutator-divisions past the brushes.

6. The combination, with the commutator, of air-jets directed upon the same, and blast mechanism operating in time with the commutator, and having blast-spaces equal in number to the jets and wings or vanes equal in number to the division-lines of the commutator.

7. The combination, with the jets directed upon the commutator, of rotary blast mechanism loose on the armature-shaft.

8. The combination, with the commutator, of laterally-adjustable air-jets.

9. The combination, with the commutator, of oircumferentially-adjustable air-jets.

.10. The combination,with the casing for the blast mechanism, of air-jets supported therefrom and directed upon the commutator, and means for adjusting said casing circumferentially.

11. The combination, with the air-jets directed upon the commutator, of a section of 14. The combination, in a dynamo-electric machine, of casin g B, supported from the bearing for the armature-shaft, vanes W W W, mounted in slots in a carrier connected to the shaft, and air-jets J, connected with the casing.

15. The combination, in a dynamo-electric machine, of easing B, wings or vanes of hard rubber, and air-jets connected with the casing and directed upon the commutator.

16. The combination, in a dynamo-electric machine, 01- casing B, pipes J, carrying the airjets, and set-screws V.

17. The combination, with a dynamo-electric machine, of the barrel D, connected with the armature-shaft by slot and spline, wings W, &c., a casing for the same, and air-jets directed upon the commutator.

18. The combination, with'the commutator, of casing B, pipes J, and support P, having a recess communicating with the air-blast chamber and the ducts carrying pipes J.

19. The combination, in a dynamo-electric machine, of the air-jets directed upon the commutator, the casing B, the outlet and inlet pipes arranged at opposite extremities of the enlarged air-space, and the screen or gauze over the inlet-pipe.

Signed at New York, in the county of New York and State of New York, this 28th day of October, A. D. 1882.

ELIHU THoMsoN.

Witnesses:

THOMAS TOOMEY, GEO.- O. GOFFIN. 

